Extensions.XPathSelectElements Method (XNode, String, IXmlNamespaceResolver)


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Selects a collection of elements using an XPath expression, resolving namespace prefixes using the specified IXmlNamespaceResolver.

Namespace:   System.Xml.XPath
Assembly:  System.Xml.Linq (in System.Xml.Linq.dll)

public static IEnumerable<XElement> XPathSelectElements(
	this XNode node,
	string expression,
	IXmlNamespaceResolver resolver


Type: System.Xml.Linq.XNode

The XNode on which to evaluate the XPath expression.

Type: System.String

A String that contains an XPath expression.

Type: System.Xml.IXmlNamespaceResolver

A IXmlNamespaceResolver for the namespace prefixes in the XPath expression.

Return Value

Type: System.Collections.Generic.IEnumerable<XElement>

An IEnumerable<T> of XElement that contains the selected elements.

You can use this method to evaluate XPath expressions that contain namespace prefixes.

Although the ordering of returned collections is not specified in the XML XPath Language 1.0 Recommendation, this extension method returns nodes in document order.

Note that nodes are returned in document order even when you use a reverse axis, such as preceding-sibling or ancestor-or-self.

This example creates an XML tree that contains a namespace. It uses an XmlReader to read the XML document. It then gets an XmlNameTable from the XmlReader, and an XmlNamespaceManager from the XmlNameTable. It uses the XmlNamespaceManager when selecting the list of elements.

                string markup = @"
<aw:Root xmlns:aw='http://www.adventure-works.com'>
    <aw:Child1>child one data 1</aw:Child1>
    <aw:Child1>child one data 2</aw:Child1>
    <aw:Child1>child one data 3</aw:Child1>
    <aw:Child2>child two data 4</aw:Child2>
    <aw:Child2>child two data 5</aw:Child2>
    <aw:Child2>child two data 6</aw:Child2>
XmlReader reader = XmlReader.Create(new StringReader(markup));
XElement root = XElement.Load(reader);
XmlNameTable nameTable = reader.NameTable;
XmlNamespaceManager namespaceManager = new XmlNamespaceManager(nameTable);
namespaceManager.AddNamespace("aw", "http://www.adventure-works.com");
IEnumerable<XElement> elements = root.XPathSelectElements("./aw:Child1", namespaceManager);
foreach (XElement el in elements)

This example produces the following output:

<aw:Child1 xmlns:aw="http://www.adventure-works.com">child one data 1</aw:Child1>
<aw:Child1 xmlns:aw="http://www.adventure-works.com">child one data 2</aw:Child1>
<aw:Child1 xmlns:aw="http://www.adventure-works.com">child one data 3</aw:Child1>

.NET Framework
Available since 3.5
Available since 4.0
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